Avalanche Forecast

Issued: Apr 22nd, 2016 9:12AM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Wet Slabs, Loose Wet and Cornices.

Avalanche Canada pgoddard, Avalanche Canada

Spring conditions. While the freezing level remains high, wet slabs will be the primary concern.

Summary

Weather Forecast

On Saturday, light rain is forecast, with light to moderate SW winds and the freezing level around 2500 m. A cold front arriving on Sunday brings 10-20 cm snow, with the freezing level falling to around 1700 m by afternoon. Skies start to clear on Monday.

Avalanche Summary

Most commercial operations have closed for the season, and observations are becoming sparse.

Snowpack Summary

Monitoring the overnight freeze of the snow surface is very important during the spring. If the snow surface does not freeze overnight or if the crust is only a few cm thick, the effect of daytime heating and solar radiation will weaken the snowpack much more quickly than it would if there is a well frozen thick crust. This is because the crust must first melt before the sun can weaken the snowpack. Deeply buried weak layers in the mid snowpack and near the ground still have the potential to wake up and become active with a rapid warm up. While unlikely, releases on these deeply buried weak layers would result in very large avalanches. Glide cracks are widespread, active, and best avoided. Cornices are large, fragile, and could trigger deep slab avalanches that run to valley bottoms. The snowpack in many areas has become isothermal, meaning the snowpack is 0 degrees Celsius throughout. An isothermal snowpack is more prone to full depth wet slab avalanches during the heat of the day.

Problems

Wet Slabs

An icon showing Wet Slabs
Wet slabs remain possible until temperatures drop significantly.
Avoid slopes with glide cracks. >Be aware of the potential for large, deep avalanches. >

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

3 - 6

Loose Wet

An icon showing Loose Wet
Rain or sun can weaken snow surface layers and lead to loose wet avalanches in steep terrain.
Be cautious of steep terrain if it is warm or raining, especially if the snow is moist or wet. >Watch for surface clues such as sluffing off of cliffs and pinwheeling. These are red flags that should prompt you to reevaluate the conditions. >

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Cornices

An icon showing Cornices
Watch out for overhanging cornices.
Stay well back from cornices. >Pay attention to overhead hazards like cornices. >Cornice releases have the potential to trigger deeply buried weak layers. >

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1 - 4

Valid until: Apr 23rd, 2016 2:00PM

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